| Message ID | 1421601875-9436-3-git-send-email-sylvain.rochet@finsecur.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Le 18/01/2015 18:24, Sylvain Rochet a écrit : > Prepare_enable on rising edge, disable_unprepare on falling edge. Reduce Please re-write which "edge" we are talking about: "... falling edge of the Vbus signal" for example. > power consumption if USB PLL is not already necessary for OHCI or EHCI. Is a verb missing in the previous sentence? > If USB host is not connected we can sleep with USB PLL stopped. > > This driver does not support suspend/resume yet, not suspending if we > are still attached to an USB host is fine for what I need, this patch > allow suspending with USB PLL stopped when USB device is not currently > used. Can you please make it more clear. Several separated sentences seem necessary here. > Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com> > --- > drivers/usb/gadget/udc/atmel_usba_udc.c | 96 ++++++++++++++++++++++++--------- > drivers/usb/gadget/udc/atmel_usba_udc.h | 4 ++ > 2 files changed, 74 insertions(+), 26 deletions(-) > > diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c > index e207d75..9cce50a 100644 > --- a/drivers/usb/gadget/udc/atmel_usba_udc.c > +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c > @@ -315,6 +315,38 @@ static inline void usba_cleanup_debugfs(struct usba_udc *udc) > } > #endif > > +static int start_clock(struct usba_udc *udc) > +{ > + int ret; > + > + if (udc->clocked) > + return 0; > + > + ret = clk_prepare_enable(udc->pclk); > + if (ret) > + return ret; > + ret = clk_prepare_enable(udc->hclk); > + if (ret) { > + clk_disable_unprepare(udc->pclk); > + return ret; > + } > + > + udc->clocked = true; > + return ret; > +} > + > +static int stop_clock(struct usba_udc *udc) > +{ > + if (!udc->clocked) > + return 0; > + > + clk_disable_unprepare(udc->hclk); > + clk_disable_unprepare(udc->pclk); > + > + udc->clocked = false; > + return 0; > +} > + > static int vbus_is_present(struct usba_udc *udc) > { > if (gpio_is_valid(udc->vbus_pin)) > @@ -1719,42 +1751,56 @@ static irqreturn_t usba_udc_irq(int irq, void *devid) > return IRQ_HANDLED; > } > > -static irqreturn_t usba_vbus_irq(int irq, void *devid) > +static irqreturn_t usba_vbus_irq_thread(int irq, void *devid) > { > struct usba_udc *udc = devid; > int vbus; > + int ret; > + unsigned long flags; > > /* debounce */ > udelay(10); > > - spin_lock(&udc->lock); > + mutex_lock(&udc->vbus_mutex); > > /* May happen if Vbus pin toggles during probe() */ > - if (!udc->driver) > + spin_lock_irqsave(&udc->lock, flags); > + if (!udc->driver) { > + spin_unlock_irqrestore(&udc->lock, flags); > goto out; > + } > + spin_unlock_irqrestore(&udc->lock, flags); I'm not sure that the protection by spin_lock is needed above. > > vbus = vbus_is_present(udc); > if (vbus != udc->vbus_prev) { > if (vbus) { > + ret = start_clock(udc); > + if (ret) > + goto out; > + > + spin_lock_irqsave(&udc->lock, flags); > toggle_bias(1); > usba_writel(udc, CTRL, USBA_ENABLE_MASK); > usba_writel(udc, INT_ENB, USBA_END_OF_RESET); > + spin_unlock_irqrestore(&udc->lock, flags); > } else { > + spin_lock_irqsave(&udc->lock, flags); > udc->gadget.speed = USB_SPEED_UNKNOWN; > reset_all_endpoints(udc); > toggle_bias(0); > usba_writel(udc, CTRL, USBA_DISABLE_MASK); > - if (udc->driver->disconnect) { > - spin_unlock(&udc->lock); > + spin_unlock_irqrestore(&udc->lock, flags); > + > + stop_clock(udc); > + > + if (udc->driver->disconnect) > udc->driver->disconnect(&udc->gadget); > - spin_lock(&udc->lock); > - } > } > udc->vbus_prev = vbus; > } > > out: > - spin_unlock(&udc->lock); > + mutex_unlock(&udc->vbus_mutex); > > return IRQ_HANDLED; > } > @@ -1762,7 +1808,7 @@ out: > static int atmel_usba_start(struct usb_gadget *gadget, > struct usb_gadget_driver *driver) > { > - int ret; > + int ret = 0; > struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget); > unsigned long flags; > > @@ -1772,31 +1818,29 @@ static int atmel_usba_start(struct usb_gadget *gadget, > udc->driver = driver; > spin_unlock_irqrestore(&udc->lock, flags); > > - ret = clk_prepare_enable(udc->pclk); > - if (ret) > - return ret; > - ret = clk_prepare_enable(udc->hclk); > - if (ret) { > - clk_disable_unprepare(udc->pclk); > - return ret; > - } > - > + mutex_lock(&udc->vbus_mutex); > udc->vbus_prev = 0; > if (gpio_is_valid(udc->vbus_pin)) > enable_irq(gpio_to_irq(udc->vbus_pin)); > > /* If Vbus is present, enable the controller and wait for reset */ > - spin_lock_irqsave(&udc->lock, flags); > if (vbus_is_present(udc) && udc->vbus_prev == 0) { > + ret = start_clock(udc); > + if (ret) > + goto out; > + > + spin_lock_irqsave(&udc->lock, flags); > toggle_bias(1); > usba_writel(udc, CTRL, USBA_ENABLE_MASK); > usba_writel(udc, INT_ENB, USBA_END_OF_RESET); > + spin_unlock_irqrestore(&udc->lock, flags); > > udc->vbus_prev = 1; > } > - spin_unlock_irqrestore(&udc->lock, flags); > > - return 0; > +out: > + mutex_unlock(&udc->vbus_mutex); > + return ret; > } > > static int atmel_usba_stop(struct usb_gadget *gadget) > @@ -1816,8 +1860,7 @@ static int atmel_usba_stop(struct usb_gadget *gadget) > toggle_bias(0); > usba_writel(udc, CTRL, USBA_DISABLE_MASK); > > - clk_disable_unprepare(udc->hclk); > - clk_disable_unprepare(udc->pclk); > + stop_clock(udc); > > udc->driver = NULL; > > @@ -1997,6 +2040,7 @@ static int usba_udc_probe(struct platform_device *pdev) > return PTR_ERR(hclk); > > spin_lock_init(&udc->lock); > + mutex_init(&udc->vbus_mutex); > udc->pdev = pdev; > udc->pclk = pclk; > udc->hclk = hclk; > @@ -2049,9 +2093,9 @@ static int usba_udc_probe(struct platform_device *pdev) > > if (gpio_is_valid(udc->vbus_pin)) { > if (!devm_gpio_request(&pdev->dev, udc->vbus_pin, "atmel_usba_udc")) { > - ret = devm_request_irq(&pdev->dev, > - gpio_to_irq(udc->vbus_pin), > - usba_vbus_irq, 0, > + ret = devm_request_threaded_irq(&pdev->dev, > + gpio_to_irq(udc->vbus_pin), NULL, > + usba_vbus_irq_thread, IRQF_ONESHOT, > "atmel_usba_udc", udc); > if (ret) { > udc->vbus_pin = -ENODEV; > diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h > index a70706e..3ceed76 100644 > --- a/drivers/usb/gadget/udc/atmel_usba_udc.h > +++ b/drivers/usb/gadget/udc/atmel_usba_udc.h > @@ -308,6 +308,9 @@ struct usba_udc { > /* Protect hw registers from concurrent modifications */ > spinlock_t lock; > > + /* Mutex to prevent concurrent start or stop */ > + struct mutex vbus_mutex; > + > void __iomem *regs; > void __iomem *fifo; > > @@ -321,6 +324,7 @@ struct usba_udc { > struct clk *pclk; > struct clk *hclk; > struct usba_ep *usba_ep; > + bool clocked; > > u16 devstatus; Otherwise, it looks okay, so once little corrections done, you can add my: Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Thanks, bye,
Hello Nicolas, On Mon, Jan 19, 2015 at 05:55:18PM +0100, Nicolas Ferre wrote: > Le 18/01/2015 18:24, Sylvain Rochet a écrit : > > Prepare_enable on rising edge, disable_unprepare on falling edge. Reduce > > Please re-write which "edge" we are talking about: "... falling edge of > the Vbus signal" for example. > > > power consumption if USB PLL is not already necessary for OHCI or EHCI. > > Is a verb missing in the previous sentence? > > > If USB host is not connected we can sleep with USB PLL stopped. > > > > This driver does not support suspend/resume yet, not suspending if we > > are still attached to an USB host is fine for what I need, this patch > > allow suspending with USB PLL stopped when USB device is not currently > > used. > > Can you please make it more clear. Several separated sentences seem > necessary here. Maybe :) Proposal: Start clocks on rising edge of the Vbus signal, stop clocks on falling edge of the Vbus signal. If USB PLL is not necessary for other USB drivers (e.g. OHCI and EHCI) it will reduce power consumption by switching off the USB PLL if no USB Host is currently connected to this USB Device. We are using Vbus GPIO signal to detect Host presence. If Vbus signal is not available then the device stay continuously clocked. Note this driver does not support suspend/resume yet, it may stay clocked if USB Host is still connected when suspending. For what I need, forbidding suspend from userland if we are still attached to an USB host is fine, but we might as well add suspend/resume to this driver in the future. > > /* May happen if Vbus pin toggles during probe() */ > > - if (!udc->driver) > > + spin_lock_irqsave(&udc->lock, flags); > > + if (!udc->driver) { > > + spin_unlock_irqrestore(&udc->lock, flags); > > goto out; > > + } > > + spin_unlock_irqrestore(&udc->lock, flags); > > I'm not sure that the protection by spin_lock is needed above. I'm not sure too, it was already in a spinlock area, I obviously kept it because it was not the purpose of this patch. This seem to be in mirror of atmel_usba_start() which does: spin_lock_irqsave(&udc->lock, flags); udc->devstatus = 1 << USB_DEVICE_SELF_POWERED; udc->driver = driver; spin_unlock_irqrestore(&udc->lock, flags); … but vbus_pin IRQ is not yet enabled. Same for atmel_usba_stop() which disable vbus_pin IRQ before setting udc->driver to NULL, but without spinlock this time (why?, this should be consistent IMHO). I don't know if it is guaranteed that IRQ does not fire nor continue to run after disable_irq() returns, especially for threaded IRQ. If the following sequence might happen: atmel_usba_stop() disable_irq(vbus) usba_vbus_irq_thread() called lately check for (!udc->driver) and continue udc->driver = NULL; if (udc->driver->disconnect) *CRASH* Then the patch should be modified to protect udc->driver with the vbus mutex. In this case the previous implementation wasn't perfect too, the atmel_usba_stop() does not lock around the NULLification of driver, Moreover the spinlock is (and was) unlocked in VBUS interrupt just before calling udc->driver->disconnect, which makes udc->driver actually not locked anywere. If the previous sequence possible ? If no, udc->driver does not need locking, if yes, it is currently not locked enough. Sylvain
On Mon, 19 Jan 2015 18:46:31 +0100 Sylvain Rochet <sylvain.rochet@finsecur.com> wrote: > Hello Nicolas, > > > On Mon, Jan 19, 2015 at 05:55:18PM +0100, Nicolas Ferre wrote: > > Le 18/01/2015 18:24, Sylvain Rochet a écrit : > > > Prepare_enable on rising edge, disable_unprepare on falling edge. Reduce > > > > Please re-write which "edge" we are talking about: "... falling edge of > > the Vbus signal" for example. > > > > > power consumption if USB PLL is not already necessary for OHCI or EHCI. > > > > Is a verb missing in the previous sentence? > > > > > If USB host is not connected we can sleep with USB PLL stopped. > > > > > > This driver does not support suspend/resume yet, not suspending if we > > > are still attached to an USB host is fine for what I need, this patch > > > allow suspending with USB PLL stopped when USB device is not currently > > > used. > > > > Can you please make it more clear. Several separated sentences seem > > necessary here. > > Maybe :) > > > Proposal: > > Start clocks on rising edge of the Vbus signal, stop clocks on > falling edge of the Vbus signal. > > If USB PLL is not necessary for other USB drivers (e.g. OHCI and EHCI) > it will reduce power consumption by switching off the USB PLL if no USB > Host is currently connected to this USB Device. > > We are using Vbus GPIO signal to detect Host presence. If Vbus signal is > not available then the device stay continuously clocked. > > Note this driver does not support suspend/resume yet, it may stay > clocked if USB Host is still connected when suspending. For what I need, > forbidding suspend from userland if we are still attached to an USB host > is fine, but we might as well add suspend/resume to this driver in the > future. > > > > > > /* May happen if Vbus pin toggles during probe() */ > > > - if (!udc->driver) > > > + spin_lock_irqsave(&udc->lock, flags); > > > + if (!udc->driver) { > > > + spin_unlock_irqrestore(&udc->lock, flags); > > > goto out; > > > + } > > > + spin_unlock_irqrestore(&udc->lock, flags); > > > > I'm not sure that the protection by spin_lock is needed above. > > I'm not sure too, it was already in a spinlock area, I obviously kept it > because it was not the purpose of this patch. According to the comment placed above this test it's here to prevent any action triggered by the vbus pin irq while the driver is not properly probed yet. You could use: set_irq_flags(vbus_irq, IRQF_NOAUTOEN); before calling devm_request_threaded_irq. This will keep the irq disabled instead of enabling it at request time. Moreover, this simplify the vbus_irq request code (which disables the irq just after requesting it). > > This seem to be in mirror of atmel_usba_start() which does: > > spin_lock_irqsave(&udc->lock, flags); > udc->devstatus = 1 << USB_DEVICE_SELF_POWERED; > udc->driver = driver; > spin_unlock_irqrestore(&udc->lock, flags); > > … but vbus_pin IRQ is not yet enabled. > > > Same for atmel_usba_stop() which disable vbus_pin IRQ before setting > udc->driver to NULL, but without spinlock this time (why?, this should > be consistent IMHO). > > > I don't know if it is guaranteed that IRQ does not fire nor continue to > run after disable_irq() returns, especially for threaded IRQ. And yes, disable_irq waits for all irq handler termination, including threaded irqs: see [1], [2]. > > > If the following sequence might happen: > atmel_usba_stop() > disable_irq(vbus) > usba_vbus_irq_thread() called lately > check for (!udc->driver) and continue > udc->driver = NULL; > if (udc->driver->disconnect) > *CRASH* > > Then the patch should be modified to protect udc->driver with the vbus > mutex. > > In this case the previous implementation wasn't perfect too, the > atmel_usba_stop() does not lock around the NULLification of driver, > > Moreover the spinlock is (and was) unlocked in VBUS interrupt just > before calling udc->driver->disconnect, which makes udc->driver actually > not locked anywere. > > If the previous sequence possible ? If no, udc->driver does not need > locking, if yes, it is currently not locked enough. If you rework the vbus_irq request as I suggested I think you can get rid of this !udc->driver test, and thus drop the locking around it ;-). Best Regards, Boris [1]http://lxr.free-electrons.com/source/kernel/irq/manage.c#L432 [2]http://lxr.free-electrons.com/source/kernel/irq/manage.c#L92
Le 19/01/2015 21:15, Boris Brezillon a écrit : > On Mon, 19 Jan 2015 18:46:31 +0100 > Sylvain Rochet <sylvain.rochet@finsecur.com> wrote: > >> Hello Nicolas, >> >> >> On Mon, Jan 19, 2015 at 05:55:18PM +0100, Nicolas Ferre wrote: >>> Le 18/01/2015 18:24, Sylvain Rochet a écrit : >>>> Prepare_enable on rising edge, disable_unprepare on falling edge. Reduce >>> >>> Please re-write which "edge" we are talking about: "... falling edge of >>> the Vbus signal" for example. >>> >>>> power consumption if USB PLL is not already necessary for OHCI or EHCI. >>> >>> Is a verb missing in the previous sentence? >>> >>>> If USB host is not connected we can sleep with USB PLL stopped. >>>> >>>> This driver does not support suspend/resume yet, not suspending if we >>>> are still attached to an USB host is fine for what I need, this patch >>>> allow suspending with USB PLL stopped when USB device is not currently >>>> used. >>> >>> Can you please make it more clear. Several separated sentences seem >>> necessary here. >> >> Maybe :) >> >> >> Proposal: >> >> Start clocks on rising edge of the Vbus signal, stop clocks on >> falling edge of the Vbus signal. >> >> If USB PLL is not necessary for other USB drivers (e.g. OHCI and EHCI) >> it will reduce power consumption by switching off the USB PLL if no USB >> Host is currently connected to this USB Device. >> >> We are using Vbus GPIO signal to detect Host presence. If Vbus signal is >> not available then the device stay continuously clocked. Typo: s/stay/stays/ >> Note this driver does not support suspend/resume yet, it may stay >> clocked if USB Host is still connected when suspending. For what I need, >> forbidding suspend from userland if we are still attached to an USB host >> is fine, but we might as well add suspend/resume to this driver in the >> future. Sylvain, thanks for having rephrased this part! It looks clear. >>>> /* May happen if Vbus pin toggles during probe() */ >>>> - if (!udc->driver) >>>> + spin_lock_irqsave(&udc->lock, flags); >>>> + if (!udc->driver) { >>>> + spin_unlock_irqrestore(&udc->lock, flags); >>>> goto out; >>>> + } >>>> + spin_unlock_irqrestore(&udc->lock, flags); >>> >>> I'm not sure that the protection by spin_lock is needed above. >> >> I'm not sure too, it was already in a spinlock area, I obviously kept it >> because it was not the purpose of this patch. > > According to the comment placed above this test it's here to prevent > any action triggered by the vbus pin irq while the driver is not > properly probed yet. > You could use: > > set_irq_flags(vbus_irq, IRQF_NOAUTOEN); > > before calling devm_request_threaded_irq. > This will keep the irq disabled instead of enabling it at request time. > Moreover, this simplify the vbus_irq request code (which disables the > irq just after requesting it). > >> >> This seem to be in mirror of atmel_usba_start() which does: >> >> spin_lock_irqsave(&udc->lock, flags); >> udc->devstatus = 1 << USB_DEVICE_SELF_POWERED; >> udc->driver = driver; >> spin_unlock_irqrestore(&udc->lock, flags); >> >> … but vbus_pin IRQ is not yet enabled. >> >> >> Same for atmel_usba_stop() which disable vbus_pin IRQ before setting >> udc->driver to NULL, but without spinlock this time (why?, this should >> be consistent IMHO). >> >> >> I don't know if it is guaranteed that IRQ does not fire nor continue to >> run after disable_irq() returns, especially for threaded IRQ. > > And yes, disable_irq waits for all irq handler termination, including > threaded irqs: see [1], [2]. > >> >> >> If the following sequence might happen: >> atmel_usba_stop() >> disable_irq(vbus) >> usba_vbus_irq_thread() called lately >> check for (!udc->driver) and continue >> udc->driver = NULL; >> if (udc->driver->disconnect) >> *CRASH* >> >> Then the patch should be modified to protect udc->driver with the vbus >> mutex. >> >> In this case the previous implementation wasn't perfect too, the >> atmel_usba_stop() does not lock around the NULLification of driver, >> >> Moreover the spinlock is (and was) unlocked in VBUS interrupt just >> before calling udc->driver->disconnect, which makes udc->driver actually >> not locked anywere. >> >> If the previous sequence possible ? If no, udc->driver does not need >> locking, if yes, it is currently not locked enough. > > If you rework the vbus_irq request as I suggested I think you can get > rid of this !udc->driver test, and thus drop the locking around it ;-). > > Best Regards, > > Boris > > [1]http://lxr.free-electrons.com/source/kernel/irq/manage.c#L432 > [2]http://lxr.free-electrons.com/source/kernel/irq/manage.c#L92 Thanks Sylvain for having described the problem lengthly and Boris for your detailed explanation and suggestion concerning this sequence. So, if you can re-send a new version and also add the stable tags as suggested by Felipe, it would be really cool. Bye,
diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c index e207d75..9cce50a 100644 --- a/drivers/usb/gadget/udc/atmel_usba_udc.c +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c @@ -315,6 +315,38 @@ static inline void usba_cleanup_debugfs(struct usba_udc *udc) } #endif +static int start_clock(struct usba_udc *udc) +{ + int ret; + + if (udc->clocked) + return 0; + + ret = clk_prepare_enable(udc->pclk); + if (ret) + return ret; + ret = clk_prepare_enable(udc->hclk); + if (ret) { + clk_disable_unprepare(udc->pclk); + return ret; + } + + udc->clocked = true; + return ret; +} + +static int stop_clock(struct usba_udc *udc) +{ + if (!udc->clocked) + return 0; + + clk_disable_unprepare(udc->hclk); + clk_disable_unprepare(udc->pclk); + + udc->clocked = false; + return 0; +} + static int vbus_is_present(struct usba_udc *udc) { if (gpio_is_valid(udc->vbus_pin)) @@ -1719,42 +1751,56 @@ static irqreturn_t usba_udc_irq(int irq, void *devid) return IRQ_HANDLED; } -static irqreturn_t usba_vbus_irq(int irq, void *devid) +static irqreturn_t usba_vbus_irq_thread(int irq, void *devid) { struct usba_udc *udc = devid; int vbus; + int ret; + unsigned long flags; /* debounce */ udelay(10); - spin_lock(&udc->lock); + mutex_lock(&udc->vbus_mutex); /* May happen if Vbus pin toggles during probe() */ - if (!udc->driver) + spin_lock_irqsave(&udc->lock, flags); + if (!udc->driver) { + spin_unlock_irqrestore(&udc->lock, flags); goto out; + } + spin_unlock_irqrestore(&udc->lock, flags); vbus = vbus_is_present(udc); if (vbus != udc->vbus_prev) { if (vbus) { + ret = start_clock(udc); + if (ret) + goto out; + + spin_lock_irqsave(&udc->lock, flags); toggle_bias(1); usba_writel(udc, CTRL, USBA_ENABLE_MASK); usba_writel(udc, INT_ENB, USBA_END_OF_RESET); + spin_unlock_irqrestore(&udc->lock, flags); } else { + spin_lock_irqsave(&udc->lock, flags); udc->gadget.speed = USB_SPEED_UNKNOWN; reset_all_endpoints(udc); toggle_bias(0); usba_writel(udc, CTRL, USBA_DISABLE_MASK); - if (udc->driver->disconnect) { - spin_unlock(&udc->lock); + spin_unlock_irqrestore(&udc->lock, flags); + + stop_clock(udc); + + if (udc->driver->disconnect) udc->driver->disconnect(&udc->gadget); - spin_lock(&udc->lock); - } } udc->vbus_prev = vbus; } out: - spin_unlock(&udc->lock); + mutex_unlock(&udc->vbus_mutex); return IRQ_HANDLED; } @@ -1762,7 +1808,7 @@ out: static int atmel_usba_start(struct usb_gadget *gadget, struct usb_gadget_driver *driver) { - int ret; + int ret = 0; struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget); unsigned long flags; @@ -1772,31 +1818,29 @@ static int atmel_usba_start(struct usb_gadget *gadget, udc->driver = driver; spin_unlock_irqrestore(&udc->lock, flags); - ret = clk_prepare_enable(udc->pclk); - if (ret) - return ret; - ret = clk_prepare_enable(udc->hclk); - if (ret) { - clk_disable_unprepare(udc->pclk); - return ret; - } - + mutex_lock(&udc->vbus_mutex); udc->vbus_prev = 0; if (gpio_is_valid(udc->vbus_pin)) enable_irq(gpio_to_irq(udc->vbus_pin)); /* If Vbus is present, enable the controller and wait for reset */ - spin_lock_irqsave(&udc->lock, flags); if (vbus_is_present(udc) && udc->vbus_prev == 0) { + ret = start_clock(udc); + if (ret) + goto out; + + spin_lock_irqsave(&udc->lock, flags); toggle_bias(1); usba_writel(udc, CTRL, USBA_ENABLE_MASK); usba_writel(udc, INT_ENB, USBA_END_OF_RESET); + spin_unlock_irqrestore(&udc->lock, flags); udc->vbus_prev = 1; } - spin_unlock_irqrestore(&udc->lock, flags); - return 0; +out: + mutex_unlock(&udc->vbus_mutex); + return ret; } static int atmel_usba_stop(struct usb_gadget *gadget) @@ -1816,8 +1860,7 @@ static int atmel_usba_stop(struct usb_gadget *gadget) toggle_bias(0); usba_writel(udc, CTRL, USBA_DISABLE_MASK); - clk_disable_unprepare(udc->hclk); - clk_disable_unprepare(udc->pclk); + stop_clock(udc); udc->driver = NULL; @@ -1997,6 +2040,7 @@ static int usba_udc_probe(struct platform_device *pdev) return PTR_ERR(hclk); spin_lock_init(&udc->lock); + mutex_init(&udc->vbus_mutex); udc->pdev = pdev; udc->pclk = pclk; udc->hclk = hclk; @@ -2049,9 +2093,9 @@ static int usba_udc_probe(struct platform_device *pdev) if (gpio_is_valid(udc->vbus_pin)) { if (!devm_gpio_request(&pdev->dev, udc->vbus_pin, "atmel_usba_udc")) { - ret = devm_request_irq(&pdev->dev, - gpio_to_irq(udc->vbus_pin), - usba_vbus_irq, 0, + ret = devm_request_threaded_irq(&pdev->dev, + gpio_to_irq(udc->vbus_pin), NULL, + usba_vbus_irq_thread, IRQF_ONESHOT, "atmel_usba_udc", udc); if (ret) { udc->vbus_pin = -ENODEV; diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.h b/drivers/usb/gadget/udc/atmel_usba_udc.h index a70706e..3ceed76 100644 --- a/drivers/usb/gadget/udc/atmel_usba_udc.h +++ b/drivers/usb/gadget/udc/atmel_usba_udc.h @@ -308,6 +308,9 @@ struct usba_udc { /* Protect hw registers from concurrent modifications */ spinlock_t lock; + /* Mutex to prevent concurrent start or stop */ + struct mutex vbus_mutex; + void __iomem *regs; void __iomem *fifo; @@ -321,6 +324,7 @@ struct usba_udc { struct clk *pclk; struct clk *hclk; struct usba_ep *usba_ep; + bool clocked; u16 devstatus;
Prepare_enable on rising edge, disable_unprepare on falling edge. Reduce power consumption if USB PLL is not already necessary for OHCI or EHCI. If USB host is not connected we can sleep with USB PLL stopped. This driver does not support suspend/resume yet, not suspending if we are still attached to an USB host is fine for what I need, this patch allow suspending with USB PLL stopped when USB device is not currently used. Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com> --- drivers/usb/gadget/udc/atmel_usba_udc.c | 96 ++++++++++++++++++++++++--------- drivers/usb/gadget/udc/atmel_usba_udc.h | 4 ++ 2 files changed, 74 insertions(+), 26 deletions(-)